1. Field
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly to transmitting signals at varying powers.
2. Background
Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, etc. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Examples of such multiple-access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.
A wireless communication network may include a number of base stations that can support communication for a number of user equipments (UEs). A UE may communicate with a base station via the downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station. Further, communications between mobile devices and base stations may be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth. In addition, mobile devices can communicate with other mobile devices (and/or base stations with other base stations) in peer-to-peer wireless network configurations.
To supplement conventional base stations, additional low power base stations can be deployed to provide more robust wireless coverage to mobile devices. For example, low power base stations (e.g., which can be commonly referred to as Home NodeBs or Home eNBs, collectively referred to as H(e)NBs, femto nodes, femtocell nodes, pico nodes, micro nodes, etc.) can be deployed for incremental capacity growth, richer user experience, in-building or other specific geographic coverage, and/or the like. In some configurations, such low power base stations are connected to the Internet via broadband connection (e.g., digital subscriber line (DSL) router, cable or other modem, etc.), which can provide the backhaul link to the mobile operator's network. In this regard, low power base stations are often deployed in homes, offices, etc. without consideration of a current network environment. Thus, low power base stations can be subject to, or can cause, substantial interference with other base stations (e.g., other low power base stations and/or macro base stations) in a wireless network.
Some concepts have been developed to address such interference, including cell range expansion (CRE), which allows a device to be served by a low power base station even where another low power base station or high power base station are near enough to cause interference. This can be provided by using an interference coordination scheme, such as enhanced inter-cell interference coordination (eICIC) to coordinate resources among base stations (e.g., using negotiations over a backhaul link between the base stations). Communications from the base stations, however, can still be hindered by requiring use of the interference coordination scheme since such schemes often result in at least one base station not utilizing protected resources negotiated by another base station.
As the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE technology. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.